A turbine casing comprises: a turbine casing body, which covers a rotor of a steam turbine from the outer side, and in which is formed an exhaust port through which steam is horizontally exhausted; an overhanging part that horizontally widens from the outer surface of the turbine casing body; and a support part that supports the overhanging part on a baseplate; the support part restraining vertical displacement of the overhanging part relative to the baseplate, and securing the overhanging part to the baseplate so as to allow the overhanging part to be horizontally deformed or displaced.

The steam turbine has a plurality of expansion stages and stator blades upstream at least one of the expansion stages; in order to regulate steam flow inside the steam turbine and maximize turbine efficiency, the angular positions of the stator blades are controlled for example by an external control unit through e.g. a command rod during operation of the steam turbine.

A control system is provided for a turbine valve. The turbine valve has a first coil and a second coil to control or sense movement of a mechanical valve positioner. Two valve positioners are provided with each valve positioner having two drive circuits to drive the first and second coils. Switches are provided such that only one drive circuit is connected to each coil at a time. The control system may also include a hydraulic pilot valve section and a main hydraulic valve section. Feedbacks are used to determine a pilot valve error and a main valve error which are combined to determine a turbine valve error. The turbine valve error is repeatedly determined to minimize the error.

A turbine stator blade (21) includes a pressure side (21P) extending in a radial direction intersecting a flow direction of steam, and facing upstream in the flow direction. A slit (5) extending in the radial direction and capturing a liquefied component of the steam is formed on a downstream side of the pressure side (21P). A hydrophilic uneven region (6) having a liquid film capacity greater than that of the pressure side (21P) by being recessed in a depth direction intersecting the pressure side (21P) is formed in a further upstream position than the slit (5). The hydrophilic uneven region (6) has a depth in the depth direction increasing and a flow resistance decreasing toward downstream and toward the slit (5).

A turbine stator blade (21) includes a pressure side (21P) extending in a radial direction intersecting a flowing direction of steam and facing upstream in the flowing direction. A slit (5) capturing droplets generated by liquefaction of the steam is formed on a downstream side of the pressure side (21P). A fine uneven region (6), which guides the droplets attached to the pressure side (21P) in the radial direction such that the droplets are moved toward the slit (5) and from upstream toward downstream, is formed in a further upstream position than the slit (5). The fine uneven region (6) has a flow resistance to the droplets gradually increasing from inward to outward in the radial direction.

A method for manufacturing a stage of a steam turbine comprising the steps of milling a block of material to define a sector having a plurality of blades, each blade having an external surface; machining an opening in the external surface of at least one of the blades; machining a cavity in fluid communication with the opening; the step of machining the cavity being performed by wire electric discharge machining.

A steam turbine includes: a partition section that partitions a high-pressure stage and a low-pressure stage; and a pressure regulation valve that regulates a pressure of extraction steam. The pressure regulation valve includes: a plurality of flow rate regulation valves; and a plurality of flow path compartments that correspond to the respective flow rate regulation valves and that communicate with the low-pressure stage side relative to the partition section through respective nozzle holes. The plurality of flow path compartments are arranged over the entire partition section in a circumferential direction in a region including an outer peripheral side of the pressure regulation valve relative to the partition section as a whole. The partition section includes a bypass passage that makes the high-pressure stage side and the low-pressure stage side communicate with each other without passing through the pressure regulation valve.

A steam turbine hollow stationary blade is able to reduce the amount of water droplets captured on a blade surface. The steam turbine hollow stationary blade, which has a cavity therein, includes a partition wall dividing the cavity into a pressure chamber on a leading edge side and an exhaust chamber on a trailing edge side, at least one steam inlet hole connecting the pressure chamber and an outside of the stationary blade to each other, and at least one pressure conditioning hole connecting the pressure chamber and the exhaust chamber. Total opening area of the pressure conditioning hole is smaller than total opening area of the steam inlet hole.

A flexible coordinated control method adapted to a thermal power unit in a deep peak-regulating operation includes: adding a reverse compensation channel from a fuel quantity instruction to a power generation load instruction on a basis of a traditional coordinated control system of a boiler-following mode; meanwhile, constructing a flexible factor by using a main steam flow quantity signal, and correcting a gain of the reverse compensation channel by the flexible factor in a product mode to obtain a reverse power generation load instruction bias value; and correcting the power generation load instruction of the unit by using the reverse power generation load instruction bias value, so as to give priority to guaranteeing the control quality of a power generation load and a throttle pressure before a steam turbine under conventional load conditions and give priority to guaranteeing the combustion stability under deep peak-regulating conditions.

Provided is an electrohydrostatic actuation system including an emergency shut-off circuit to be actuated stably with a simple configuration. The electrohydrostatic actuation system includes: a hydraulic cylinder (24) including a piston (25) to which a valve element is connected, a first chamber (24A), and a second chamber (24B); a hydraulic pump (21) configured to supply hydraulic fluid to the first chamber (24A) or the second chamber (24B); a servo motor (M) configured to drive the hydraulic pump (21); a shuttle valve (11) configured to establish communication to a downstream side under a state in which a hydraulic pressure generated by the hydraulic pump (21) is maintained; a solenoid valve (12) configured to receive the hydraulic pressure via the shuttle valve (11) as a pilot pressure; and a logic valve (13) including a first port configured to receive the pilot pressure from the solenoid valve (12), and a second port to be communicated to the first chamber (24A) of the hydraulic cylinder (24). When the solenoid valve (12) is brought to a de-energized state, the pilot pressure of the logic valve (13) is released, and the logic valve (13) causes the hydraulic fluid in the first chamber (24A) communicated to the second port to flow into the second chamber (24B) so that emergency shut-off of the valve element is achieved by a return spring (26).